Comparative Study of Different H₂S Donors as Vasodilators and Attenuators of Superoxide-Induced Endothelial Damage

In the last years, research proofs have confirmed that hydrogen sulfide (H2S) plays an important role in various physio-pathological processes, such as oxidation, inflammation, neurophysiology, and cardiovascular protection; in particular, the protective effects of H2S in cardiovascular diseases were demonstrated. The interest in H2S-donating molecules as tools for biological and pharmacological studies has grown, together with the understanding of H2S importance. Here we performed a comparative study of a series of H2S donor molecules with different chemical scaffolds and H2S release mechanisms. The compounds were tested in human serum for their stability and ability to generate H2S. Their vasorelaxant properties were studied on rat aorta strips, and the capacity of the selected compounds to protect NO-dependent endothelium reactivity in an acute oxidative stress model was tested. H2S donors showed different H2S-releasing kinetic and produced amounts and vasodilating profiles; in particular, compound 6 was able to attenuate the dysfunction of relaxation induced by pyrogallol exposure, showing endothelial protective effects. These results may represent a useful basis for the rational development of promising H2S-releasing agents also conjugated with other pharmacophores